Float-zone and Czochralski-type crystals were implanted with protons or deuterons at about 50K. Electron paramagnetic resonance measurements revealed a new signal in the spectrum of Czochralski-type (O-rich) material. This signal was strongly temperature-dependent, and exhibited a transition from monoclinic-I to orthorhombic-I symmetry between 180 and 240K and between 230 and 290K, in proton-implanted and deuteron-implanted samples, respectively. The g-tensor which was observed at low temperatures, as well as a large 29Si hyperfine splitting which was associated with a unique Si site, were typical of a vacancy-type defect with the unpaired electron confined to a dangling-bond orbital. Proton hyperfine splittings showed that a single H atom was incorporated into the defect, and strongly suggested that the defect contained only one vacancy. The results permitted the definite attribution of the signal to VOH0; the neutral charge state of the monovacancy-O defect (A center), which contained a single H atom. It was found that the H atom could jump quite easily between the 2 equivalent sites which lay in the (110) mirror-plane of the defect.

Identification of the Oxygen-Vacancy Defect Containing a Single Hydrogen Atom in Crystalline Silicon P.Johannesen, B.Bech Nielsen, J.R.Byberg: Physical Review B, 2000, 61[7], 4659-66